SWIM BLADDER DISEASE *Cause and Cure*

Hi all; Am new to this.....I am desperate....My 10 year old fantail has had constant swim bladder for the past 6 months at least.... I have tried everything recommended!!!!!!!!!! except the needle thing and cod liver oil....Do you soak the spirulina in the oil before feeding it???? I hand feed this fish.... He is so gutsy I don't have the heart to kill him.... Slight pressure on his bladder used to work, but not anymore... Does anyone have a diagaram of the bladder so I could try that needle thing as a last resort....Barring anything else ; and nothing works, I think he has suffered long enough and would like some humane idea on putting him to sleep....I was thinking of putting tank water in a ziplock with air, and putting him in the freezer...I think the gradual temperature change would slow his system down till he went comatose???